1. Field of the Invention
This invention is directed to monoclonal antibodies against antigens associated with potyviruses, hybrid cell lines producing these antibodies, and methods of using these monoclonal antibodies.
2. Description of the Background Art
The potyviruses are a group of aphid transmitted plant viruses with flexuous filamentous particles that are 680-900 nm long and about 11 mm in diameter. The virions typically are composed of up to about 2,000 subunits of a single capsid protein species which has a molecular weight of about 32-36 Kd. The capsid proteins are arranged in a helix which encloses the genome. The viruses induce the formation of characteristic cytoplasmic inclusions which are serologically unreleated to their respective viral capsid protein.
Members of the potyvirus group comprise the largest and economically most important group of plant viruses and affect a wide range of crop plants. Thus, the detection of these viruses would be of considerable interest.
Among those techniques of interest for use in detecting potyviruses are those which involve the use of antibodies. Serological relationships among potyviruses are, however, highly complex. Most of the definitive potyviruses have been shown to be serologically related to some degree to at least one other potyvirus, but present techniques have failed to detect any relationship between many potyviruses. Polyclonal antisera show cross-reactivity to various degrees with only a few closely related virus strains of the same virus used to immunize and fail to cross-react with more distantly related viruses. Polyclonal antisera produced to denatured potyviruses, however, show a higher degree of cross-reactivity with different potyviruses. (Shepard, et al., Virology, 58:464, 1974). Monoclonal antibodies produced to specific potyvirus members have proven to be specific for the immunizing virus or show only limited cross-reactivity with less related potyviruses (Dougherty, et al., Virology, 144:66, 1985; Gugerli, et al., Journal of General Virology, 64:2471, 1983; Hill, et al., Journal of General Virology, 65:525, 1984).
As a result of the lack of broadly reactive antibodies specific to potyviruses, at present it would be extremely difficult to design an effective immunodiagnostic test for their detection. This is because immunodiagnostic tests using existing antibodies would require either multiple assays or the use of pooled antibody reagents in order to attempt detection of most potyviruses encountered in ecological samples. Unfortunately, it is unlikely that either of these approaches are feasible since using multiple assays is cumbersome and inefficient and the use of pooled antibody reagents is inherently likely to result in a loss of sensitivity. As a consequence, a considerable need remains for a antibody which is broadly reactive with potyviruses, but not other plant viruses, that can be used immunodiagnostically.